In recent years, the fairness of automated employment decision tools (AEDTs) has received increasing attention. In November 2021, the New York City Council passed Local Law 144, which mandates bias audits of these systems. From 5 July 2023 (initially 1 January 2023 and then initially postponed to 15 April 2023), companies that use AEDTS to screen candidates for employment or employees for promotion in the city must have these systems audited by an independent entity. Rules proposed by the Department of Consumer and Worker Protection (DCWP) specify that bias must be determined using impact ratios that compare the outcomes for subgroups based on sex/gender and race/ethnicity categories at a minimum.

In this this post, we evaluate how the metrics proposed by the DCWP to calculate impact ratios for regression systems can be fooled by unexpected distributions and tweaking the data.